English physician. Studied hair and eye color among the Irish in 1861, and assumed these variants to be important racial markers; developed an index of nigrescence to measure the ratio of light- to dark-haired individuals in a population. Conducted major anthropometric survey of Great Britain, published as The Races of Britain: Contribution to the Anthropology of Western Europe (1885) and conducted a second survey in Europe in 1891. Probably the first person to survey geographical regions in anthropometric detail.